Electronic mail (e-mail) enables computer users to conveniently share information. Frequently, however, network packets carrying e-mail are dropped due to network traffic or physical transmission problems. Even when successfully delivered, recipients sometimes delete or otherwise fail to read received e-mail. Thus, a user sending e-mail often cannot not be sure the intended recipient ever read or received the e-mail.
Some e-mail software packages, such as cc:Mail™ available from Lotus™ Corporation of Cambridge, Mass., provide a “return receipt” option when sending e-mail. E-mail software that receives e-mail specifying “return receipt” can automatically send back a receipt message indicating that the intended recipient received the e-mail. Some software packages permit an administrator or user to disable “return receipt” functions and, thus, prevent transmission of receipts back to e-mail senders.
E-mail contents can include text messages entered in an e-mail editor and/or attachment files (attachments). Recent surveys indicate that more than 50% of information transmitted via e-mail is transmitted in the form of attachments. Many e-mail software packages enable a user receiving an e-mail attachment to easily forward received attachments to other recipients. Thus, an attachment may be quickly disseminated to a large number of individuals unknown to the user originally sending the attachment.